TEXT TO HTML REGEX METHOD

       
//TEXT TO HTML REGEX METHOD
public string TextToHtml(string inputtext ) 
{ 
inputtext = Regex.Replace(inputtext, "<", "<") ; 
inputtext = Regex.Replace(inputtext, ">", ">") ; 
inputtext = Regex.Replace(inputtext, @"http://(.\S+)", "$1") ; 
inputtext = Regex.Replace(inputtext, @"ftp://(.\S+)", "$1ftp://$1\">$1;") ; 
inputtext = Regex.Replace(inputtext, @"news://(.\S+)", "$1;") ; 
inputtext = Regex.Replace(inputtext, @"(\S+\@.*\..\S+)", "$1;") ; 
inputtext = Regex.Replace(inputtext, "\n", "
") ; 
inputtext = Regex.Replace(inputtext, @"\s\s", "  ") ; 
return inputtext ; 
} 
        

REGEX expression for HTML Tag cleaning

C# code for replacing either a specific tag, or removing a series of potentially malicious tags from an HTML string:

 
using System.Text.RegularExpressions 

// Replace BODY tag with "<div id="advert/">" (for later replacement with ad code, for example): 
strContent = Regex.Replace(strContent, @"</?(?I:BODY)(.|\N)*?>", "<div id="advert/">"); 


//Malicious script: replace any and all of script / body /embed / object / frameset / frame / iframe / meta / ling /style with "") 
strContent = Regex.Replace(strContent, @"</?(?I:SCRIPT|BODY|EMBED|OBJECT|FRAMESET|FRAME|IFRAME|META|LINK|STYLE)(.|\N)*?>", "");

Regular Expression to convert URL to Hyperlink

  using System.Text.RegularExpressions; 
//this will turn all urls in the input parameter string sInput into 
HTML hyperlinks

public string ConvertURLsToHyperlinks(string sInput) 
{ 
return Regex.Replace(sInput, @"(\bhttp://[^ ]+\b)", @"$0"); 
}